A barrel nut (also known as steel cross dowel or dowel nut) is a specialized nut, and is commonly used in aerospace and ready to assembly furniture, and knockdown furniture applications. It is used to bolt thin sheet metal parts to larger, often billet or forged, parts. The barrel nut is a round slug, or formed sheet metal part with threads perpendicular to the length of the nut. The nut sits in a hole inside the forging and a standard machine screw is threaded into the barrel nut from outside the sheet metal. They are preferred over a standard nut and bolt, because they do not require a flange to be machined or forged onto the receiving part, thus reducing weight.
Barrel nuts are also common in flat-pack furniture, where long bolts and barrel nuts are used to hold together T joints in chipboard sheets.
- Smith, Carroll (1990). Carroll Smith's Nuts, Bolts, Fasteners, and Plumbing Handbook. MotorBooks/MBI Publishing Company. pp. 107–108. ISBN 0879384069.